$ { \left[\begin{array}{rr}{-1} & {4} \\ {2} & {-2}\end{array}\right]+\left[\begin{array}{rr}{1} & {-1} \\ {2} & {-2}\end{array}\right] = {?} } $
Solution: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{-1}+{1} & {4}+{-1} \\ {2}+{2} & {-2}+{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {3} \\ {4} & {-4}\end{array}\right]}$